1. Technical Field
The present invention relates to a device for monitoring the fluid level of a supply reservoir, in particular of a hydraulic motor vehicle brake system, comprising a float that has a magnet for actuating a switch or a sensor.
2. Description of Related Art
In a hydraulic motor vehicle brake system, the brake fluid required is contained in the supply reservoir, and the fluid level is monitored by the magnet that is used to activate the switching contacts. When the level of the brake fluid drops, the switching contacts are activated. This signal is evaluated in an electronic control unit, and the driver of the motor vehicle can be warned by a lamp, or a similar device. As this occurs, it must be ensured that the supply reservoir is always filled with a minimum of brake fluid in order not to jeopardize the operation of the brake system. Normally, devices for monitoring the level of a fluid reservoir are used, in which the float operates a Reed contact as soon as the float adopts a predetermined position (operating point) when the fluid level in the reservoir falls below a defined minimum. Operation of the Reed contact triggers a warning signal that is noticeable to the driver, whereupon the driver must take appropriate countermeasures.
DE 37 16 135 A1 e.g. discloses a device of this type. This device includes a float with a magnet, which latter has an annular design and is shifted by way of a radial cutout in the float into its installation position around a central bore of the float. Sidewalls of the cutout include mounting means that secure the magnet in its installation position.
It is considered disadvantageous that the magnet can rupture and get detached from the float when it is damaged due to manufacture or during the assembly. The float will be stuck thereby, causing failure of the device.